Splicing devices are used for joining component belts which, as a general rule, are used in the automatic population of printed circuit boards or ceramic substrates.
As a general rule, SMD components are accommodated in the component belts. Depending on the size of the components, the belts are designed to be 8, 12, 16 or 24 mm wide. Component belts are particularly suitable for automation, since the components are already separated and the packing in the belt ensures the most comprehensive safeguard against mixing up components. As a result of the large supply of components per belt or per track, a very high effectiveness is achieved during the passage of the belt.
However, the effectiveness of the overall population system decreases considerably when it is stopped briefly in order to insert a new belt.
The population performance can be increased by the end of a component belt which has not yet been emptied being joined in a manner suitable for the automatic machine to the start of a full component belt. However, a precondition here is that the joining of the component belts can be performed quickly. In addition, high requirements are placed on the tearing strength of the splice point and on the dimensional stability of the transport perforation on both sides of the splice point (DIN EC 286 Part 3, September 1987, page 5, item 4.6).
In the patent DE 4210139 C1, a splicing strip consisting of plastically deformable metal has already been proposed for joining component belts, which strip is provided with a perforation associated with the transport perforation of the component belts and can be anchored in the belt material of the belts to be joined by extensions projecting from its joining face.
The splicing strip is joined to the component belts by means of pressing.
German utility model G 9314832.1 proposes the generic splicing device in the form of splicing tongs for this purpose.
In order to join the component belts, the metal splicing strip is plugged onto the lower jaw of the splicing tongs, over the centering pins, and then the end of the first belt and the end of the second belt are plugged on over the splicing strip, in order to join said ends by closing the tongs over the splicing strip.
Joining the component belts via the splicing strip functions satisfactorily, but the splicing device still has some disadvantages in terms of handling.
In particular, when the second belt end is inserted, it is necessary to let go of the first belt end, since the second hand is needed to hold the tongs.
In this case, it often occurs that the first belt end jumps out of the centering pins on the lower jaw of the splicing device again.
A further disadvantage is that the start of the new belt and the end of the old belt are not matched exactly to each other, and the ends have to be cut to shape with scissors. In addition, when cutting the ends with the scissors, in particular in the case of belts with very small components, it occurs that a certain gap remains between the ends, and a component is missing from this position in the belt course.
This in turn leads to faults in automatic placement machines, in particular when processing the components, and/or to erroneously populated printed circuit boards.
Furthermore, EP 0 893 948 A has disclosed a splicing device for joining component belts (1, 2) with the aid of metal splicing strips (5), which are likewise provided with a perforation (6) associated with the transport perforation (4) of the component belts (1 and 2) and are anchored in the belt material by extensions (7) projecting from their joining face. The splicing device includes two jaws (10 and 11) which can be pressed together, with one jaw bearing at least two centering pins (23) arranged in relation to each other at one or many times the pitch spacing of the transport perforation (4), and the other jaw (11) having holes (31) in which the opposite centering pins (23) can be sunk when the jaws (10, 11) are closed.
In CH 676 703 A, a splicing device is disclosed which is provided with a cutting device constructed in the form of two separate knives.